Cutting device with resilient locking mechanism



April 1965 cs. w. ELDERS CUTTING DEVICE WITH RESILIENT LOCKING MECHANISM Filed Jan. 9, 19s:

INVENTOR. GERALD w ELDERS 60% M Powell F IG. 2.

ATTORNEY.

United States Patent 3,177,037 CUTTING DEVICE WITH REILIENT LOCKING This invention relates generally to improvements in a locking mechanism for a cutting device, and more particularly to an improved means for selectively retaining a bit in a holder.

Certain features of the present assembly are disclosed and claimed in copending application, Serial No. 36,916, filed June 17, 1960, now Patent No. 3,127,153, of which the present application is a continuation-in-part.

An important objective achieved by the present invention is the elimination of set screws, wedges, transverse pins and other means heretofore utilized to lock a cutter bit into a holder.

Furthermore, in order to effect removal or insertion of the bit in the previously mentioned conventional construc tions, various tools such as wrenches, drifts and the like had to be used. The instant locking mechanism eliminates the use of these implements and affords a simple system for causing ready attachment and detachment of a cutter bitin a holder.

Another important object is to provide a bit-locking mechanism that can be conveniently and advantageously utilized in cutter-type machines or in boring-type machines now being used throughout the industry today to mine coal, salt, ores or other minerals both above-and under ground. This improved mechanism can be used also in certain drilling type machines having large size units, commonly called coal recovery drills.

Still another important objective is achieved by the pro vision of a solid, resilient block member made of rubber or the like which is attached to the holder and acts to exert pressure between a pin and bit shank for retaining the bit in a holder socket. The resilient block member will not break, corrode, pack with dirt or dust and will remain resilient and operative for an indefinite period, thereby greatly minimizing repair costs and production loss because of machine shut-down while making repairs and replacement of parts. I

Yet another important object is atforded by the structural arrangement of the resilient block member and its connection to the holder so as to preclude accidental or unintentional'removal of the block member and to assure the exertion of a pressure on the bit shank at all times while held in the holder socket.

Another important advantage obtained by the above structure is that the pin can be intentionally withdrawn from the holder socket upon application of suificient pulling force axially on the bit, the pin being depressible with the'block member to permit such a result.

An important object is provided by a bit-locking mechanism that is capable of coacting with a bit having any shaped shank, such as rectangular, square, hexangular, circular or the like. While in the preferred embodiment of the invention, only a single bit-locking mechanism is used to engage operatively one side of the bit shank in the manner suggested previously, it is advantageous that any number of the mechanisms can be used for various or any size bit shanks as is desired, subject only to the dictates of good design. a

An important object is achieved by the structural arrangement of the resilient block and its mounting in the holder aperture, the block having a tapered front portion converging forwardly substantially from an intermediate shoulder away from the wall defining an enlarged inner aperture portion to provide a space into which the block can compress and which is of a gradually increasing size so that foreign material cannot collect but rather is ejected upon block expansion into such space.

Another important object is provided by the tapered front block end on which the pin head seats in that the block expands laterally into the aperture space upon-axial depression and precludes the pin head from embedding itself into the block and thereby prevents mutilation of the block.

It is an important objective to provide a bit-locking mechanism that is simple and durable in construction, economical to manufacture, efiicient in operation and which can be quickly and easily manipulated by any one Without any instruction.

The foregoing and numerous other objects and advantages of the invention will more clearly appear from the following detailed description of a preferred embodiment, particularly when considered in connection with the accompanying drawing, in which:

FIG. 1 is a side elevation-a1 view of the bit and holder;

FIG. 2 is an end elevational view as seen from the left of FIG. 1, but being partially cut away to show the internal locking mechanism;

FIG. 3 is an end elev-ational view as seen from the right of FIG. 1, and

FIG. 4 is an exploded elevational view of the block member and pin.

Referring now by characters of reference to the drawing, and first to FIGS. 1 and 2, it is seen that the bit and holder construction includes a holder generally indicated at 10 having a body 11 with depending end extensions 12. The holder body 11 is provided with a top-open socket 13, best'shown in FIG. 2, adapted to receive a bit referred to at 14. The socket 13 is also open at the bottom to allow the end of the bit 14 to project therethrough. The socket 13 is located substantially centrally of the holder body 11 between the end extensions 12 so that the downwardly projecting end of the bit 14 is located between such extensions 12.

The bit 14 includes a shank 15, the configuration of which closely approximates the shape of the socket 13. The bit 14 includes an enlarged head portion 16 adapted to carry a carbide tip 17 that constitutes the cutting ele ment.

When fully inserted in holder 10, the shank 15 closely interfitsthe socket 13 and the shoulder 29 formed by the enlarged head portion 16 abuts the outermost face of holder body 11 immmediately adjacent the upper end of socket 13;

The details of the bit-locking mechanism utilized with this bit and bolder are bestshown in FIGS. 2 and 4.

Formed in'one side wall 21 of the holder body 11 is an aperture 22 that communicates with the socket 13. More particularly, the aperture 22 includes an enlarged inner portion 23 immediately adjacent the socket 13 and an outwardly divergent outer portion 24, the aperture portions 23 and 24 being interconnected by an inwardly facing abutment 25.

Plugged into aperture 22 is a conforming resilient block member 26 formed of rubber or a similar solid material. It is seen that the block member 26 includes a rear portion 27 that is tapered forwardly to conform to the divergent configuration of the outer aperture portion 24-. The front end of the rear portion 24 extends laterally outwardly to provide an annular shoulder 39 that faces rearwardly to engage the abutment 25 upon insertion of the block member 26 into aperture 22.

Formed as an integral part of the block member 26 is a front portion 31 that tapers or converges forwardly substantially from the shoulder 30 to the front end 32 of the block member. When inserted into the aperture 22, the

because of its structural shape and relationship to the holder wall defining the aperture portion 23, thefront block portion 31 will eject any foreign material that may gather into the space 29., It is preferred that the front end 32 of the block member 26 lie flush with the inner wall of the holder defining the socket 13.

A pin 33 includes a shank 34 and a forwardly tapered, enlarged head 35. The diameter of pin shank 34 is'slightly larger than the diameter of a bore 36 provided longitudinally and axially through the resilient block member 26. This relationship is best shown in FIG. 4.

When assembled, the pin shank is press-fitted into the innermost end of longitudinal bore '36 so'that the pin head 35 abuts the front end 32 of block member 26. To

preclude unintentional withdrawal of the pin shank 34 after insertion into bore 36, the end of the pin shank is provided witha small flange 37 that is received in a compatible anular recess 40 formed in bore'36 at the rear end of the rear block member 27. Thenvthis lock button unit, constituting the block member 26 and pin 33 assembled, is plugged into the holder aperture 22 to provide the struct'urebest shown in FIG.'2.

Formed in one side of bit shank-15 is a recess or indent 41 that is aligned with and adapted to receive the pin head 35 when the bit 14 is completely inserted into the holder socket 13. Under the resilient force exerted by V the block member 26, the pin 33 retains the bit 14 in the .holder 10 and precludes unintentional withdrawal.

Of course, the bit 12 can be intentionally removed from the socket 13 by applying sufficient pull to the bit 14 so that the pin head 35 rides out of the recess 41 against the resilient loading of the solid block member 26, the pin head 35 being depressible axially with the front block portion 31 so that the front block portion 31 expands laterally into the space 29. the pin head 35 extends slightly beyond the periphery of the front end 32 of the front block portion 31 so that the pin head 35 does not press into the body of the block member 26 to cause any damage or multilation of the block member. However, the pin head 35 does not extend laterally asufiicient distance to block the opening of the space 29 to the socket 13. v It is thought that the assembly and operation of the bit and block havebecome fully apparent from the fore going detailed description of parts, but for completeness ofdisclosure the functional advantages will be briefly described. V f

First, the pin 33 is assembled to the blockmember-Zfi by pressing the pin shank 34 into the bore 36 until the pin head 35 abuts the front end 32 and the endflange 37 snaps into the bore recess 40. Then this unit is pressed into the holder aperture 22. When installed, the front block portion 31 is received in the inner aperture portion 23, the rearwa'rdly facing shoulder snapping outwardly into engagement with the inwardly facing abutment 25 to preclude subsequent with unintentional withdrawal. In addition, the. forwardly tapered rear block portion 27 interfits the outer divergent aperture portion 24 such that the peripheral walls engage to preclude movement of the block member 26 into the socket 13. a

When assembled as described above, the pin head extends into the socket 13. When the bit 14 is attached to the holder 10 by inserting the shank 15 into the socket 13, the bit shank engages the pin head 35 and depresses it outwardly under the resilient loading of the front block portion 31 as permitted by the lateral expansion of the block 31 into the appropriate space 29 immediately ad- It will he noted that jacent the socket'13. Upon complete insertion and seating of the bit shank 15 into thesocket 13, the pin head is transmitted to the abutting surfaces between the bit 14 and the holder 1% and acts to seat the bit firmly in the socket 13. Because the bit 14 cannot be ripped out of Y the socket 13 by the cutting force, it is seen that the stresses are relieved from thebit-locking mechanism, and specifically relieved between the pin 33 and its coacting recess 41 formed in the bit shank 15. r

. Although the invention has been described by making detailed reference to a single preferred embodiment, such detail is to be understood in an instructive, rather than in any restrictive sense,many variants being possible within the scope of the claims hereunto appended.

I claim as my invention:

1. A cutting device comprising:

(a) a holder provided with a socket,

' (b) a bit having a shank received in said socket, the

shank being provided with a recess,

(c) the holder being provided with an aperture communicating withsaid socket, said'aperture including an enlarged portion immediately adjacent said socket, said aperture being reduced intermediate its ends tov provide outwardly and inwardly facing shoulders,

(d) a resilient block disposed in said aperture, said block'including an end located in. said enlarged aperture portion and tapered toward said socket to provide a lateral space between the tapered block end holder, said block being reduced intermediat its ends to engage said shoulders, and

(e) a pin carried by said block, said pin having a 'head, seating on said tapered 'block end and extending into said socket to interfit said shank recess.

2. The combination and arrangementof elements as recited above in claim 1, but further characterized in that said pin head seats on and extends laterally beyond the periphery of the tapered block end, yet does not block the space provided between the tapered block end and the holder.

3. A cutting device comprising:

(a) a holder provided with a socket,

(b) a. bit having a shank received in said. socket, the

, shank being provided with a'recess,

(c) the holder being provided with an aperture communicating with said socket, the aperture including an enlarged inner portion partiallydefined by an inwardly facing abutment, ,7 V

(d) a resilient block disposed in said aperture, said block including a front end located in the enlarged inner aperture portion, the front block end being tapered toward said socket to provide a gradually in creasing space between the tapered block end and said holder which communicates with said socket,

(2) said block engaging said inwardly facing abutment'rearwardly of said front tapered block end, and

V (f) a pin carried'by said block, said pin having a head seating on the front block end and extending an outwardly divergent outer portion and an enlarged inner portion partially defined by an inwardly facing abutment,

(d) a resilient block disposed in said aperture, said block including a front portion located in the enlarged inner aperture portion, the front block portion being tapered toward said socket and providing a gradually increasing space between the front block portion and holder which communicates with said socket, and the block including a rear portion located in the divergent outer aperture portion and tapered toward said front portion to engage said holder, said front block portion having its large end greater than the small end of said rear block portion to provide a shoulder engaging said abutment, and

(e) a pin carried by said block, said pin having a head seating on the small end of said tapered front block portion and extending into said socket to interfit said shank recess.

5. A cutting device comprising:

(a) a holder provided with a socket,

(b) a bit having a shank received in said socket, the

shank being provided with a recess,

(0) the holder being provided with an aperture communicating with said socket, said aperture including an enlarged inner portion, an outwardly divergent outer portion, and an intermediate inwardly facing abutment therebetween,

(d) a resilient block disposed in said aperture, said block including a rearwardly divergent rear portion disposed in said divergent outer aperture portion, a rearwardly facing shoulder at the small forward end of said rear block portion engaging said abutment, and a front portion disposed in said inner aperture portion converging forwardly substantially from said shoulder to provide a gradually increasing space therebetween which communicates with said socket, and

(e) a pin carried by said block, said pin having a head seating on said front block portion and extending into said socket to interfit said shank recess.

6. A cutting device comprising:

(a) a holder provided with a socket,

(b) a bit having a shank received in said socket, the

shank being provided with a recess,

(0) the holder being provided with an aperture communicating with said socket, said aperture including an enlarged inner portion, an outwardly divergent outer portion, and an intermediate inwardly facing abutment therebetween,

(d) a resilient block disposed in said aperture, said block including a rearwardly divergent rear portion disposed in the divergent outer aperture portion, a rearwardly facing shoulder at the small forward end of said rear block portion engaging said abutment, and a front block portion received in said enlarged inner portion converging forwardly substantially from said shoulder to provide a gradually increasing space between the front block portion and said holder which communicates with said socket, and

(e) a pin carried in said block, said pin having a head seating on the small end of said front block portion and extending into said socket to interfit said shank recess, said pin head extending laterally beyond the periphery of the small end of said front block portion yet not blocking the entrance to said space.

References Cited by the Examiner UNITED STATES PATENTS 1,830,117 11/31 Lee.

2,212,153 8/40 Eaton et al. 26770 2,719,017 9/55 Mordarski.

2,962,304 11/60 Lung.

2,996,291 8/ 61 Krekeler.

40 BENJAMIN HERSH, Primary Examiner. 

1. A CUTTING DEVICE COMPRISING: (A) A HOLDER PROVIDED WITH A SOCKET, (B) A BIT HAVING A SHANK RECEIVED IN SAID SOCKET, THE SHANK BEING PROVIDED WITH A RECESS, (C) THE HOLDER BEING PROVIDED WITH AN APERTURE COMMUNICATING WITH SAID SOCKET, SAID APERTURE INCLUDING AN ENLARGED PORTION IMMEDIATELY ADJACENT SAID SOCKET, SAID APERTURE BEING REDUCED INTERMEDIATE ITS ENDS TO PROVIDE OUTWARDLY AND INWARDLY FACING SHOULDERS, (D) A RESILIENT BLOCK DISPOSED IN SAID APERTURE, SAID BLOCK INCLUDING AN END LOCATED IN SAID ENLARGED APERTURE PORTION AND TAPERED TOWARD SAID SOCKET TO PROVIDE A LATERAL SPACE BETWEEN THE TAPERED BLOCK END HOLDER, SAID BLOCK BEING REDUCED INTERMEDIATE ITS ENDS TO ENGAGE SAID SHOULDERS, AND (E) A PIN CARRIED BY SAID BLOCK, SAID PIN HAVING A HEAD SEATING ON SAID TAPERED BLOCK END AND EXTENDING INTO SAID SOCKET TO INTERFIT SAID SHANK RECESS. 